The present invention relates to surfacing apparatus, and more particularly, to apparatus for applying a refractory alloy coating to the effective areas of valves for internal combustion engines.
The term "effective area" is used to denote a chamfer made in the head of the internal combustion engine valve and meant for providing a tight fit between the valve and the corresponding seat chamfer.
It is known that the effective areas of internal combustion engine valves are exposed to repeated contact loads and to the action of high temperatures reaching 800.degree.-1000.degree. C. In order to extend the service life of the valves the effective area thereof is coated with refractory alloys.
At present for surfacing the effective areas of internal combustion engine valves use is made of flame, plasma or high frequency operating mechanisms, respectively, which melt the refractory alloy to be applied to the effective area. A possibility of automation and simplicity of the process of surfacing the valve effective areas in the high frequency current field advantageously distinguish apparatus with a high frequency operating mechanism from other known apparatus.
There are known apparatus for surfacing the effective areas of valves, wherein assembly of a valve, i.e. placing of a refractory alloy ring on the head of the valve, and positioning of said valve into the surfacing zone is carried out manually. However, these auxiliary operations consume much time and labour, thereby causing low efficiency of such apparatus.
There are also known apparatus for surfacing valves for internal combustion engines by fusing on the effective areas of the valves refractory alloy rings, in which apparatus a valve is assembled with a ring and positioned in the surfacing zone automatically.
However, successive disposition of stationary operating mechanisms, either directly participating in the process of surfacing, i.e., the heater, or auxiliary ones, e.g., means for loading and unloading the valves, requires a drive rotor of a complex design. This drive rotor should provide conveyance of a valve to a corresponding operating station, bringing of the valve to an operating mechanism, if necessary, with a time lag for treatment, and withdrawal of the valve from said operating mechanism. The foregoing features reveal the complexity of the apparatus of this type, low reliability and difficulty of control thereof. Besides, the construction of said apparatus excludes any possibility to carry out the operations, e.g., loading and unloading, at one operating station which, naturally, causes insufficient production rate.
The object of the present invention is generally to provide an apparatus for surfacing valves for internal combustion engines by fusing refractory alloy rings on the effective areas of the valves, said apparatus featuring a simple construction.
A further object of the present invention is to provide an apparatus for surfacing valves for internal combustion engines which is simple in control and maintenance.
Another object of the present invention is to provide an apparatus for surfacing valves for internal combustion engines which is fail-safe in operation.
Still another object of the present invention is to provide an apparatus for surfacing valves, wherein feeding of a valve to a heater and to a valve clamping device, cooling of the valve being surfaced and unloading of the same are carried out at one station.
In accordance with the foregoing and other objects the invention resides in that the apparatus for surfacing valves for internal combustion engines by fusing refractory alloy rings on the effective areas of the valves comprises: a heater, a valve clamping device containing a rotation gear, a manipulator adapted to receive and to convey said valve to the heater zone simultaneously positioning said valve head downwards, a feed mechanism adapted to feed said valve to the heater and to the valve clamping device, a sprayer and an unloading chute; according to the invention said valve feed mechanism, said sprayer and said unloading chute are mounted on a platform operatively connected through a transfer gear to the manipulator to provide alternate positioning under the heater of the feed mechanism, of the sprayer and of the unloading chute.
It is preferred to mount the platform on a shaft for rotation in the horizontal plane.
To make the structure of the apparatus more simplified it is expedient that the transfer gear operatively connecting the platform to the manipulator should be formed by a toothed sector fixed on the drive shaft of the manipulator and by a toothed sector mounted on the periphery of the platform which is in meshing engagement with said toothed sector of the drive shaft.
The sprayer may be made annular and mounted at the inlet end of the unloading chute thereby preventing blocking up of the holes of the sprayer with melted metal of the fused ring and making the structure of the apparatus more simplified.
Thus, mounting of the sprayer, of the valve feed mechanism and of the unloading chute on the common platform which is operatively connected to the manipulator ensures, according to the movement of the latter, alternate positioning under the heater of said operating mechanisms, which, in turn, makes it possible to carry out at one operating station both operations, that is, surfacing and cooling, and auxiliary operations, i.e. loading and unloading.